Pneumatic tool



Sept. 28 1926.

E. PENBERTHY ET AL PNEUMATIC TOOL Filed Feb. 2. 1920 2 Sheets-Sheet 1 I lllllllla Ml llm 0 o W Sept. 28 1926;

I E. PENBERTHY ET AL 2 Sheets-Sheet 2 l atented Set. 2, 12do rare ERNEST PENBERTHY AND GEORGE E. GLASER, 0F CLEVELAND, OHIO,- ASSIGNORS T0 CHICAGO PNEUMATIC TOOL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

ENEUMATIO TOOL.

Application filed February 2, 1920. Serial No. 355,638.

Our invention relates to tools operated more particularly by compressed air and the object thereof is to produce a tool embodying several novel and advantageous features of construction which adapt it to the special use as a tie'tamping device. One of the objects of our invention is to provide simple and eflicient means for retaining the tool at the front end of a cylinder and permitting ready assembling and disassembling.

In the drawings, Fig. l is an elevation of the completetool; Fig. 2 a longitudinal section of the main portion of the tool; Figs. 3 and 4 detail views of the attaching means for the retainer sleeve; Figs. 5, 6 and 7 sections on the corresponding section lines of Fig. 2; Fig. 8 a perspective partly in section illustrating the clamping means for the hack lhi ead and F ig. 9 a detail section online 9 of teferring to the embodiment of our invention as shown in the drawings, the toolcomprises as main parts a cylinder 1, back head 2, handle 3 attached thereto as by the attaching means shown at 4, a tool 5 which is here a tie tamper and a piston 6 reciprocating Within. the bore or chamber of the cylinder. The air under pressure enters through the inlet boss 7 which leads by passage 8 to the air chamber 9 in the back head. A longitudinal passage or passages 10 lead from the passage'8" forwardly through the cylinder wall and a similar passage or passages 11 lead from the chamber 9 forwardly through the cylinder walls. Both of these passages 10 and 11 emerge into' the piston chamber through the ports 12 arranged in the same transverse plane. .The cylinder is also provided with one or more longitudinal passages 13 which communicate through ports 14. with I the extreme rear end of the piston chamber and through ports 15 with an annular groove 16 in the piston chamber which groove is located at a point intermediate the rear end of the piston chamber and the ports 12. The

' cylinder is also provided with one or more exhaust ports 17 leading directly from the piston chamber to the atmosphere. These ez'zhaust ports are located between the rear end of the piston-chamber and the ports 15.

The piston is a solid body of metal unprovided with ports or passages but made of two diameters, the head or rear portion being i of the greater diameter and the forward portion which is adapted to strike theend of the tool 5 being of the lesser diameter. There is thus provided on the piston a shoulder 18 forming a pressure area. The piston head. reciprocates within the rear end of the piston chamber which properly fits the same and such piston chamber is contracted towards its forward end by the provision of the annular enlargement 19 which fits the forward end or stem of the piston and provides a pressure chamber between it and the pressure area 18 of the piston head.

Next describing the tool retainer means the same consists of a retainer sleeve '20 fitting over the forward end of the cylinder and having a series of inturned lugs 21 which are adapted to cooperate with and fit into corresponding recesses 22 formed at the rearward edges of a corresponding series of ln s 23 formed at the extreme forward end of tFe cylinder. This retainer sleeve is adapted to be applied to the cylinder in a manner so that the lugs 21 will slide past the other lugs and then to be turned angularly and thence forwardly so as to bring the lugs 21 into engagement with the sockets 22. This sleeve 20 has an inturned flange 24 at its forward end and also an opening 25 through which the tool 5 passes. Within the sleeve is arranged a split bushing 26 having intermediate its length an annular flange 27 which is adapted to fit against the forward end of the cylinder, being held in such position with a yielding pressure by means of a rather heavy spring 28 interposed between such flange and the flange 24 of the sleeve. This bushing has a central bore through which the tool 5 passes and is adapted to receive at its inner or rearward end the impact of the collar 29 of the tool when struck by the piston, when the machine is raised from the work. It will be readily seen that the foregoing construction has for its object to increase the vibration of the tool 5, by holding said tool 5 in the path of the piston when said machine is raised from the work. The object of increasing the vibration of the tool is to cause the rock or ballast filling u on which the tool 5 operates to pack in p ace with increased speed. The bushing 26 is made in the form shown so as to be reversible which is a matter of much economy, in-

asmuch as the inner end of the bushing becomes damaged in time by the impact of the collar 29 whereupon a reversal is the equivalent of a new bushing. While spring 28 when intact operates to retain sleeve 20 in locking engagement with cylinder 1 as heretofore described, its main function is to absorb the shock of the tool and to hold bushing 27 in place. Spring 28 is therefore liable to destruction. To insure the maintenance of sleeve 20 in locked engagement with the cylinder and to guard against accident in the event of breakage of spring 28, a light coiled spring 30 is interposed between the end of the cylinder and the flange 24 of sleeve 20. This spring 30 surrounds the heavy spring 28 and is beyond the range of movement of the tool and of bushing 27 Next describing the means for attaching the back head to the cylinder, the same comprises a clamping bolt 31 extending longitudinally of the tool and through the forwardly extending flange 32 of the back head. This bolt is provided at its rearward end with a nut 33 and at its forward end with a head provided with a hook 34 which is adapted to normally engage a recess 35 in the side of the cylinder. This recess is made of greater length than the hook 34 and also extends rearwardly a distance slightly below the forward face 36 of the back head. As a result, when the nut 33 is loosened or backed off somewhat, and the bolt is pushed forward as thus permitted by the recess 35 it will be in a position to clear the face 36 and to thereby be turned angularly so as to be disengaged from the recess. The cylinder and back head may now be detached. This construction is not only simple but is advantageous in practice because the parts may be disengaged without disassembling the clamping means. All that is necessary is to loosen the nut 33, without taking it off entirely and if desired the rearward end of the bolt may be slightly rifyeted over to prevent the nut from coming 0 Describing a cycle of operation of the tool, andstarting with the piston in the position indicated and moving rearwardly, the live air which is constantly admitted through the ports and passages 10, 11 and 12 acts on the pressure area 1.8 of the piston and forces the same rearwardly because the rear piston chamber is at this time at exhaust through the exhaustports 17. The piston continues to travel rearwardly until after it has closed these exhaust ports and until the pressure area 18 of the piston has passed the annular groove 16 whereupon the live air in front of the piston head will be admitted through the ports and passages 15, 13 and 14 to the rearward end of the piston chamber and against the rearward end of the piston. As a. result the iston will be driven forcibly forward and its stem will deliver a blow to the tool 5.

The piston on its forward stroke and before it has struck the tool will cover the groove 16 and ports 15 to cut off the supply of live air to the rear end of the piston chamber and thereafter on its further forward travel the rear end of the piston will uncover the exhaust ports 17, whereupon the pressure in the rearward end of the piston chamber will be exhausted. The ports are now in condition for a repetition of the cycle of operation. The forward end of the piston is thus exposed at all times to the live air pressure and the rearward end thereof is exposed alternately to atmospheric pressure and to the same live pressure which acts on the front end of such piston.

Ive claim:

1. In combination with a fluid pressure actuated hammer including a cylinder having a series of lugs at its forward end, a tool retaining means at the forward end thereof comprising a sleeve having corresponding lugs for detachably engaging the cylinder lugs after an angular movement and also having a flange, a spring between said flange on the sleeve and cylinder for yieldinglyholding the lugs together, a bushing extending within the cylinder and a spring within the first mentioned spring and between the bushing and said flange on the sleeve.

2. In combination with a fluid pressure actuated hammer including a cylinder having a series of lugs at its forward end, a tool retaining means at the forward end thereof comprising a sleeve having corresponding lugs for detachably engaging the cylinder lugs after an angular movement and also having a flange, a sprin between said flange on the sleeve and cylinder for yieldingly holding the lugs together, a bushing extending within the cylinder and av spring within the first mentioned spring between the bushing and said flange on the sleeve, said cylinder lugs having sockets into which the sleeve lugs enter and in which they are retained by the first named spring.

3. In combination in a fluid pressure actuated hammer comprising a cylinder, 9. re versible tool-retaining bushing extending partly within said cylinder and having a portion engaging the end of the latter, a retainer sleeve, coacting means on said sleeve and cylinder whereby said sleeve is detachably locked on said cylinder, a spring engaging said cylinder and sleeve to maintain the latter in locked engagement with the former, and a spring between said sleeve and said bushing for holding the latter against the endof the c linder.

4. In com ination in a fluid pressure actuated hammer comprising a cylinder, a reversible bushing therein having an annular flange intermediate its length, which flan e bears against the cylinder end and permits apart of said bushing to extend within said cylinder, a retainer sleeveadapted to fitover the end of said cylinder, coacting locking lugs on said sleeve and cylinder, a coil spring within said sleeve for maintaining the latter in locked engagement on the cylinder, and a second coil spring within said first spring engaging the annular flange on said bushing for holding the latter against the end of said cylinder.

5. In combination in a percussive tool com rising a cylinder, a collared working tool extending, within said cylinder, a reversible bushing extending partly within said cylinder and serving as an abutment for the collar on said working tool, said bushing having on its exterior an annular flange for engagement with the end of said cylinder to limit the extending of the bushing within said cylinder, a retainer sleeve arranged for quick attachment to and detachment from said cylinder and having an inturned abutment flange at its outer end, and a coil spring encircling the outwardly projecting portion of said bushing between the flange of the latter and the abutment flange on said sleeve for yieldinglyretaining said bushing flange against the end ofsaid cylinder.

6. In combination in a percussive tool t0 comprising a cylinder, a collared working tool extending within said cylinder,*a reversible bushing extending partly Within said cylinder and serving as an abutment for the collar on said working tool, said bushing having on its exterior an annular flange for engagement with the end of said cylinder to limit the extending of the bushing within said cylinder, a retainer sleeve enclosing the rojecting portion of said busht0 ing and having an inturned abutment flange at its outer end. cooperating locking lugs on said sleeve and said cylinder, a coil spring encircling the outwardly projecting portion of said bushing between the flange on the 45 latter and the abutment flange on said sleeve for yieldingly retaining said bushing flange against the end of said cylinder, and a second coil spring within said sleeve and encircling said first spring but out of contact with the 50 latter for maintaining said lugs in interlocked position.

ERNEST PENBERTHY.

GEO. H. GLASER. 

